sys/undelete.2

   1 .\" Copyright (c) 1994
   2 .\"     Jan-Simon Pendry
   3 .\"     The Regents of the University of California.  All rights reserved.
   4 .\"
   5 .\" Redistribution and use in source and binary forms, with or without
   6 .\" modification, are permitted provided that the following conditions
   7 .\" are met:
   8 .\" 1. Redistributions of source code must retain the above copyright
   9 .\"    notice, this list of conditions and the following disclaimer.
  10 .\" 2. Redistributions in binary form must reproduce the above copyright
  11 .\"    notice, this list of conditions and the following disclaimer in the
  12 .\"    documentation and/or other materials provided with the distribution.
  13 .\" 3. All advertising materials mentioning features or use of this software
  14 .\"    must display the following acknowledgement:
  15 .\"     This product includes software developed by the University of
  16 .\"     California, Berkeley and its contributors.
  17 .\" 4. Neither the name of the University nor the names of its contributors
  18 .\"    may be used to endorse or promote products derived from this software
  19 .\"    without specific prior written permission.
  20 .\"
  21 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31 .\" SUCH DAMAGE.
  32 .\"
  33 .\"     @(#)undelete.2  8.4 (Berkeley) 10/18/94
  34 .\" $FreeBSD: src/lib/libc/sys/undelete.2,v 1.17 2006/01/22 19:49:37 truckman Exp $
  35 .\"
  36 .Dd January 22, 2006
  37 .Dt UNDELETE 2
  38 .Os
  39 .Sh NAME
  40 .Nm undelete
  41 .Nd attempt to recover a deleted file
  42 .Sh LIBRARY
  43 .Lb libc
  44 .Sh SYNOPSIS
  45 .In unistd.h
  46 .Ft int
  47 .Fn undelete "const char *path"
  48 .Sh DESCRIPTION
  49 The
  50 .Fn undelete
  51 system call attempts to recover the deleted file named by
  52 .Fa path .
  53 Currently, this works only when the named object
  54 is a whiteout in a union file system.
  55 The system call removes the whiteout causing
  56 any objects in a lower layer of the
  57 union stack to become visible once more.
  58 .Pp
  59 Eventually, the
  60 .Fn undelete
  61 functionality may be expanded to other file systems able to recover
  62 deleted files such as the log-structured file system.
  63 .Sh RETURN VALUES
  64 .Rv -std undelete
  65 .Sh ERRORS
  66 The
  67 .Fn undelete
  68 succeeds unless:
  69 .Bl -tag -width Er
  70 .It Bq Er ENOTDIR
  71 A component of the path prefix is not a directory.
  72 .It Bq Er ENAMETOOLONG
  73 A component of a pathname exceeded 255 characters,
  74 or an entire path name exceeded 1023 characters.
  75 .It Bq Er EEXIST
  76 The path does not reference a whiteout.
  77 .It Bq Er ENOENT
  78 The named whiteout does not exist.
  79 .It Bq Er EACCES
  80 Search permission is denied for a component of the path prefix.
  81 .It Bq Er EACCES
  82 Write permission is denied on the directory containing the name
  83 to be undeleted.
  84 .It Bq Er ELOOP
  85 Too many symbolic links were encountered in translating the pathname.
  86 .It Bq Er EPERM
  87 The directory containing the name is marked sticky,
  88 and the containing directory is not owned by the effective user ID.
  89 .It Bq Er EINVAL
  90 The last component of the path is
  91 .Ql .. .
  92 .It Bq Er EIO
  93 An I/O error occurred while updating the directory entry.
  94 .It Bq Er EROFS
  95 The name resides on a read-only file system.
  96 .It Bq Er EFAULT
  97 The
  98 .Fa path
  99 argument
 100 points outside the process's allocated address space.
 101 .El
 102 .Sh SEE ALSO
 103 .Xr unlink 2 ,
 104 .Xr mount_unionfs 8
 105 .Sh HISTORY
 106 The
 107 .Fn undelete
 108 system call first appeared in
 109 .Bx 4.4 Lite .